Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1997-2-5
pubmed:abstractText
The cDNAs encoding full-length type A and B phytochromes (phyA and phyB, respectively) from potato were expressed in inducible yeast systems (Saccharomyces cerevisiae and Pichia pastoris). In addition, a deletion mutant of phyB (delta 1-74) was expressed. The apoproteins were reconstituted into chromoproteins by incorporation of the native chromophore, phytochromobilin (P phi B), and of phycocyanobilin (PCB). The incorporation of P phi B yielded chromoproteins with difference absorptions lambda max at 660 and 712 nm (Pr and Pfr, respectively) for phyA, and at 665 and 723 nm for phyB. All difference maxima of PCB phytochromes are blue-shifted by several nanometers with respect to those obtained with the P phi B chromophore. The deletion construct with PCB shows difference absorption maxima at 652 and 705 nm with the Pfr absorbance considerably reduced. Time-resolved kinetic analysis of a phyB-type phytochrome by nanosecond flash photolysis was performed for the first time. Recombinant full-length phyB afforded transient absorbance changes similar (but not identical) to those of phyA from Avena, whereas the kinetic behavior of these intermediates was very different. Contrary to phyA from Avena, the I700 intermediate from phyB reconstituted with either PCB or P phi B decayed following single exponential kinetics with a lifetime of 87 or 84 microseconds, respectively, at 10 degrees C. The formation of Pfr of PCB-containing recombinant phyB (phyB-PCB) could be fitted with three lifetimes of 9, 127, and 728 ms. The corresponding lifetimes of phyB-P phi B are 22.5, 343, and 2083 ms. Whereas for phyB-PCB all three millisecond lifetimes are related to the formation of Pfr, the 2 s component of phyB-P phi B is concomitant with a rapid recovery of Pr. For recombinant potato phyA and delta 1-74 phyB, no time-resolved data could be obtained due to the limited quantities available. As described for phytochromes of other dicotelydons, the Pfr forms of full-length phyA and PhyB of potato underwent rapid dark conversion to Pr.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
7
pubmed:volume
36
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
103-11
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:8993323-Biliverdine, pubmed-meshheading:8993323-Blotting, Western, pubmed-meshheading:8993323-Cloning, Molecular, pubmed-meshheading:8993323-Gene Expression, pubmed-meshheading:8993323-Kinetics, pubmed-meshheading:8993323-Molecular Structure, pubmed-meshheading:8993323-Mutation, pubmed-meshheading:8993323-Photolysis, pubmed-meshheading:8993323-Phycobilins, pubmed-meshheading:8993323-Phycocyanin, pubmed-meshheading:8993323-Phytochrome, pubmed-meshheading:8993323-Pichia, pubmed-meshheading:8993323-Plant Proteins, pubmed-meshheading:8993323-Polymerase Chain Reaction, pubmed-meshheading:8993323-Pyrroles, pubmed-meshheading:8993323-Recombinant Proteins, pubmed-meshheading:8993323-Saccharomyces cerevisiae, pubmed-meshheading:8993323-Sequence Deletion, pubmed-meshheading:8993323-Solanum tuberosum, pubmed-meshheading:8993323-Spectrophotometry, pubmed-meshheading:8993323-Tetrapyrroles
pubmed:year
1997
pubmed:articleTitle
Recombinant type A and B phytochromes from potato. Transient absorption spectroscopy.
pubmed:affiliation
Max-Planck-Institut für Strahlenchemie, Mülheim an der Ruhr, Germany.
pubmed:publicationType
Journal Article